Planar glass panes are produced, cut to specific size, and shipped to users. Frequently, a multiplicity of glass panes of different sizes are shipped to the same customer, and are transported on a single glass shipping rack. As explained below, while this facilitates mass glass shipment, it hinders the customer in selection of the order in which individual glass panes must be removed from the shipping rack.
Currently, there are at least three apparatus in use for shipping plate glass. One means is to pack the glass plates in a wooden case, which provides good protection, but incurs a relatively high cost in construction, packing and disposal. The wood case must be inclined before opening to ensure that the glass will not fall out. This is typically achieved by leaning the case against a wall, post, or an A-frame style rack. Unless the wooden case is covered by a top, the glass can be wetted or otherwise damaged by environmental conditions. Moreover, unless all the glass panes in the case are of the same size, the panes must be moved individually and sorted to allow selection of each particular pane, as needed by the customer. This sorting operation requires space, labor, and increases the risk of breakage.
As an alternative to wooden cases, steel reusable racks are also presently in use. These racks, an embodiment of which is illustrated in FIG. 1, can be of the L-frame-type or the A-frame type. Since these frames are reusable, they offer the advantage of reduced overall cost compared to wooden racks, but they have a higher initial investment cost, and there is an additional freight cost for returning empty racks to the glass supplier. There are several different methods for securing plate glass to steel racks. These range from simple cords or ropes to padded bars that can be adjusted to suit a particular load requirement. Because the glass plate leans against the rack structure, any restraint used to secure the glass during transportation can be removed without risk of glass falling and breaking. Racks are typically constructed to be handled with forklifts, cranes or other common material handling machines.
In the case of steel racks, as in wooden racks, organizing the order of the glass on the rack is dictated by reduction of the risk of breakage. Thus, the largest sized pieces are loaded first, followed by progressively smaller panes. However, this may not be the order in which the customer desires to utilize the glass panes. Accordingly, steel racks suffer from the same shortcoming as wooden cases in that additional handling of the glass panes is necessary to arrange them in the proper order for use.
Plate glass is also shipped on harp racks or slot racks, which include a series of covered cables strung tight to a framework to act as separators and to support individual panes of glass. This type of rack is advantageous because it allows the user to store or retrieve the glass in any order necessary to facilitate efficient utilization. However, this type of rack requires more physical space for storage because each slot requires a separation area from the adjacent slot. Moreover, the overall size of the rack must physically accommodate the largest possible glass pane. Furthermore, the glass panes are not entirely separated from each other, and can scratch or damage adjacent panes when inserted or withdrawn from the rack. Finally, it is a major disadvantage of this type of rack that it can only be used on a flat floor surface, because the glass cannot be secured to the rack. Thus, the rack is unsuitable to ship the glass panes to another location.
There exists a need for a method of shipping glass plate from one facility to another that allows the customer ease of selection between the panes being shipped, and that reduces the risk of glass breakage.